Perfect Addiction [People's Choice Award Winner '15]

Sienna Lane has finally got her life the way she wants it to be.
A steady job at the local gym? Check.
An awesome sister as a roommate? Check.
A perfect boyfriend who adores and loves her? Check.
Sienna thinks she has everything figured out. That is until she discovers that her boyfriend has been screwing around with her very own sister.
Talk about humiliating.
To make things worse, god has decided to bestow upon her the presence of Kayden Williams. He's moody, resentful and has a lot of issues, but he is indeed a great fighter - perhaps one of the best if it weren't for the fact that he has been defeated in the ring by none other than Sienna's ex.
Both of them need each other more than they think they do. Kayden wants glory and Sienna needs him to fuel her revenge as well as a place to stay. She makes a deal with him to train him for the biggest fight of his life against her own ex-boyfriend in exchange for living in his apartment.
Boundaries have been set. Both Kayden and Sienna have to stick to the rules and play nice. But that is proven difficult considering the fact that maybe... they don't dislike each other as much as they think they do.
In fact, they may just be addicted to each other.
#17 on Teen Fiction
Warning: This story contains mature language/swearing. Read at your own risk.

It’s irritating Tf outta me that she at least didn’t stay in her own apartment and kick them out. If you’re not gonna kick their ass the least you could do is stay in own damn apartment and kick them out.